In primary osteosarcoma of the most common malignant bone tumor, mainly seen in the 15 to 25 youth, more men than women about doubled. Tumor of long bone metaphysis and more to the distal femur, proximal tibia and proximal humerus, the most common. Major components of the tumor for the tumor cells into bone, bone tumors and tumor-like bone. (Femur osteosarcoma (bone type). Femoral intramedullary lower ground glass density increased, the local bone tumor was a large number of radial flakes stuck in the soft tissue mass, the top of the periosteal new bone adjacent to the triangular "cuff-like.") More than 70% of the patients in the distal femur and proximal tibia. Poor prognosis.Osteosarcoma of which the following categories:
The central osteosarcoma, the most common addition to the traditional or classic central osteosarcoma, there are the following subtypes of osteosarcoma: vasodilation osteosarcoma, intraosseous well differentiated osteosarcoma and round cell osteosarcoma, in addition to high bone All are outside the differentiation of osteosarcoma is a highly malignant tumors.
1. Conventional central osteosarcoma
This type generally involve the metaphysis of long bones, particularly on both sides of the knee occurs in young adults, according to the different histological components, can be divided into type osteoblasts, cartilage-type mother cells, fibroblasts and fibrous tissue cell type osteosarcoma, to see these structures in the diagnosis of the osteosarcoma helpful. However, the potential for multi-tumor tissue of the origin and prognosis of these subtypes was no significant difference, and is currently a large number of data indicate that various types of treatment also differ, so do not value the separation of these subtypes.
2. Vasodilator osteosarcoma
This type accounts for approximately 1% of osteosarcoma, histological features: a large number of cavities filled with red blood cells separated by fibrous septa, cellular atypia is fairly obvious, accompanied by abnormal osteoclast giant cells or multinucleated giant cells, when the tumor osteoid matrix or tumor Bone rare or hard to find, often misdiagnosed as aneurysmal bone cyst or a malignant giant cell tumor. If this type of early preoperative and postoperative chemotherapy, the prognosis of patients will be greatly improved.
3. Intraosseous well differentiated osteosarcoma
This type of rare low-grade histology showed malignant fibrous bone lesions, there may be parosteal osteosarcoma, fibrous dysplasia, desmoid tumor / osteoblastoma-like, cartilage, fibrous tumor-like mucus and other organizations image. X-ray examination found that cortical bone destruction, defects contribute to the diagnosis. Low grade and high grade osteosarcoma of the difference is still totally dependent on histology, the future of the distinction between malignant osteosarcoma and osteosarcoma treatment which are to be applied molecular biology research. This type of radical resection of osteosarcoma can be treated successfully, local resection often recurrent, and often accompanied by the osteosarcoma 5% high grade osteosarcoma.
4. Round cell osteosarcoma
This type of tumor from Ewing sarcoma or similar large cell lymphoma and other malignant small cells, although the focal stromal tumor of bone, but will always appear. Recently, small cell osteosarcoma is one of the hot, because it with the malignant neuroectodermal tumor (PNET) have a chromosomal translocation t (11; 12), which made small cell osteosarcoma of bone is associated with tumor-like matrix formation of PNET, but this type of osteosarcoma and Ewing sarcoma and PNET of bone relationship remains unclear. This type of tumor is rare (about 1% of osteosarcoma), but that the type is important because it is treatment of osteosarcoma than the general poor.
Second, the superficial or surface osteosarcoma
Occurred in the bone far from the surface of osteosarcoma occurred in the more common bone osteosarcoma. These tumors have many different nomenclature, but Schajowicz so integration of these documents, based on histological and biological research, but also this osteosarcoma is divided into three subtypes: cortical next osteosarcoma, periosteal osteosarcoma and high grade superficial Table osteosarcoma. Separation of 3 very necessary, because their histological features, biological behavior and prognosis are different.
1. Cortex adjacent to osteosarcoma
The superficial type is common in osteosarcoma, occur in young adults aged 30 to 40 long bone epiphyseal side, especially after the distal femur. Radiology for a wide base attached to the bone in the cortical bone mass. Histological features of low grade malignant spindle cell tumors associated with mature trabecular bone in parallel. Occasionally, the tumor can see the lower edge of the image of cartilage tissue sarcoma, osteosarcoma, cortex adjacent to the early identification of need and myositis ossificans. On the cortex adjacent to the differentiation of osteosarcoma with the problem has been much controversy. This type of tumor recurrence after surgical treatment, with dedifferentiation, the patients with poor prognosis.
2. Periosteal osteosarcoma
The superficial type is a rare subtype of osteosarcoma, often involving the long bones of the backbone of youth. Histologically, often significantly lower or intermediate grade of cartilage components, sometimes accompanied by calcification or ossification, but in the focal area, the total can be seen thin strip of bone stromal tumor or tumor of bone. This type of shallow surface height prognosis of malignant osteosarcoma good.
3. Osteosarcoma category, highly malignant osteosarcoma superficial
This type of highly malignant osteosarcoma. Its histology and prognosis of the same conventional osteosarcoma.